Using contrast matching to understand the role of hydrophobic additives in gels

Functionalised dipeptides form gels by dilution of dipeptide solutions in organic solvents in water. We have recently observed that structural changes in micellar aggregates can be obtained by the addition of a co-solvent. Preliminary contrast matching SANS data on high pH solutions showed that the solvent is co-aggregating in the micelle to induce the change. We now need to understand if this behaviour is also reflected in the gel state or if the more hydrophobic solvent plays a different role when the system aggregates. This will be particularly useful for applications in drug storage and delivery, as the general assumption is that hydrophobic additives are encapsulated in the gel system. Here, we wish to use contrast matching approaches to match out the dipeptide in the gel state and understand if the solvent co-aggregates or is homogeneously dispersed during gelation.